/***************************************************************************/
/*                                                                         */
/*  ttload.c                                                               */
/*                                                                         */
/*    Load the basic TrueType tables, i.e., tables that can be either in   */
/*    TTF or OTF fonts (body).                                             */
/*                                                                         */
/*  Copyright 1996-2010, 2012 by                                           */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include "ttload.h"

#include "sferrors.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttload


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_lookup_table                                               */
/*                                                                       */
/* <Description>                                                         */
/*    Looks for a TrueType table by name.                                */
/*                                                                       */
/* <Input>                                                               */
/*    face :: A face object handle.                                      */
/*                                                                       */
/*    tag  :: The searched tag.                                          */
/*                                                                       */
/* <Return>                                                              */
/*    A pointer to the table directory entry.  0 if not found.           */
/*                                                                       */
FT_LOCAL_DEF( TT_Table )
tt_face_lookup_table( TT_Face face,
                      FT_ULong tag )
{
    TT_Table entry;
    TT_Table limit;
#ifdef FT_DEBUG_LEVEL_TRACE
    FT_Bool   zero_length = FALSE;
#endif


    FT_TRACE4(( "tt_face_lookup_table: %08p, `%c%c%c%c' -- ",
            face,
            ( FT_Char ) ( tag >> 24 ),
            ( FT_Char ) ( tag >> 16 ),
            ( FT_Char ) ( tag >> 8 ),
            ( FT_Char ) ( tag )));

    entry = face->dir_tables;
    limit = entry + face->num_tables;

    for ( ; entry < limit; entry++ )
    {
        /* For compatibility with Windows, we consider    */
        /* zero-length tables the same as missing tables. */
        if ( entry->Tag == tag )
        {
            if ( entry->Length != 0 )
            {
                FT_TRACE4(( "found table.\n" ));
                return entry;
            }
#ifdef FT_DEBUG_LEVEL_TRACE
            zero_length = TRUE;
#endif
        }
    }

#ifdef FT_DEBUG_LEVEL_TRACE
    if ( zero_length )
      FT_TRACE4(( "ignoring empty table\n" ));
    else
      FT_TRACE4(( "could not find table\n" ));
#endif

    return NULL;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_goto_table                                                 */
/*                                                                       */
/* <Description>                                                         */
/*    Looks for a TrueType table by name, then seek a stream to it.      */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A face object handle.                                    */
/*                                                                       */
/*    tag    :: The searched tag.                                        */
/*                                                                       */
/*    stream :: The stream to seek when the table is found.              */
/*                                                                       */
/* <Output>                                                              */
/*    length :: The length of the table if found, undefined otherwise.   */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_goto_table( TT_Face face,
                    FT_ULong tag,
                    FT_Stream stream,
                    FT_ULong *length )
{
    TT_Table table;
    FT_Error error;


    table = tt_face_lookup_table( face, tag );
    if ( table )
    {
        if ( length )
        {
            *length = table->Length;
        }

        if ( FT_STREAM_SEEK( table->Offset ))
        {
            goto Exit;
        }
    }
    else
    {
        error = SFNT_Err_Table_Missing;
    }

    Exit:
    return error;
}


/* Here, we                                                         */
/*                                                                  */
/* - check that `num_tables' is valid (and adjust it if necessary)  */
/*                                                                  */
/* - look for a `head' table, check its size, and parse it to check */
/*   whether its `magic' field is correctly set                     */
/*                                                                  */
/* - errors (except errors returned by stream handling)             */
/*                                                                  */
/*     SFNT_Err_Unknown_File_Format:                                */
/*       no table is defined in directory, it is not sfnt-wrapped   */
/*       data                                                       */
/*     SFNT_Err_Table_Missing:                                      */
/*       table directory is valid, but essential tables             */
/*       (head/bhed/SING) are missing                               */
/*                                                                  */
static FT_Error
check_table_dir( SFNT_Header sfnt,
                 FT_Stream stream )
{
    FT_Error error;
    FT_UShort nn, valid_entries = 0;
    FT_UInt has_head = 0, has_sing = 0, has_meta = 0;
    FT_ULong offset = sfnt->offset + 12;

    static const FT_Frame_Field table_dir_entry_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_TableRec

                    FT_FRAME_START( 16 ),
                    FT_FRAME_ULONG( Tag ),
                    FT_FRAME_ULONG( CheckSum ),
                    FT_FRAME_ULONG( Offset ),
                    FT_FRAME_ULONG( Length ),
                    FT_FRAME_END
            };


    if ( FT_STREAM_SEEK( offset ))
    {
        goto Exit;
    }

    for ( nn = 0; nn < sfnt->num_tables; nn++ )
    {
        TT_TableRec table;


        if ( FT_STREAM_READ_FIELDS( table_dir_entry_fields, &table ))
        {
            nn--;
            FT_TRACE2(( "check_table_dir:"
                        " can read only %d table%s in font (instead of %d)\n",
                    nn, nn == 1 ? "" : "s", sfnt->num_tables ));
            sfnt->num_tables = nn;
            break;
        }

        /* we ignore invalid tables */
        if ( table.Offset + table.Length > stream->size )
        {
            FT_TRACE2(( "check_table_dir: table entry %d invalid\n", nn ));
            continue;
        }
        else
        {
            valid_entries++;
        }

        if ( table.Tag == TTAG_head || table.Tag == TTAG_bhed)
        {
            FT_UInt32 magic;


#ifndef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
            if ( table.Tag == TTAG_head )
#endif
            has_head = 1;

            /*
             * The table length should be 0x36, but certain font tools make it
             * 0x38, so we will just check that it is greater.
             *
             * Note that according to the specification, the table must be
             * padded to 32-bit lengths, but this doesn't apply to the value of
             * its `Length' field!
             *
             */
            if ( table.Length < 0x36 )
            {
                FT_TRACE2(( "check_table_dir: `head' table too small\n" ));
                error = SFNT_Err_Table_Missing;
                goto Exit;
            }

            if ( FT_STREAM_SEEK( table.Offset + 12 ) ||
                 FT_READ_ULONG( magic ))
            {
                goto Exit;
            }

            if ( magic != 0x5F0F3CF5UL )
            {
                FT_TRACE2(( "check_table_dir:"
                            " no magic number found in `head' table\n" ));
                error = SFNT_Err_Table_Missing;
                goto Exit;
            }

            if ( FT_STREAM_SEEK( offset + ( nn + 1 ) * 16 ))
            {
                goto Exit;
            }
        }
        else if ( table.Tag == TTAG_SING)
        {
            has_sing = 1;
        }
        else if ( table.Tag == TTAG_META)
        {
            has_meta = 1;
        }
    }

    sfnt->num_tables = valid_entries;

    if ( sfnt->num_tables == 0 )
    {
        FT_TRACE2(( "check_table_dir: no tables found\n" ));
        error = SFNT_Err_Unknown_File_Format;
        goto Exit;
    }

    /* if `sing' and `meta' tables are present, there is no `head' table */
    if ( has_head || ( has_sing && has_meta ))
    {
        error = SFNT_Err_Ok;
        goto Exit;
    }
    else
    {
        FT_TRACE2(( "check_table_dir:" ));
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
        FT_TRACE2(( " neither `head', `bhed', nor `sing' table found\n" ));
#else
        FT_TRACE2(( " neither `head' nor `sing' table found\n" ));
#endif
        error = SFNT_Err_Table_Missing;
    }

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_font_dir                                              */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the header of a SFNT font file.                              */
/*                                                                       */
/* <Input>                                                               */
/*    face       :: A handle to the target face object.                  */
/*                                                                       */
/*    stream     :: The input stream.                                    */
/*                                                                       */
/* <Output>                                                              */
/*    sfnt       :: The SFNT header.                                     */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
/* <Note>                                                                */
/*    The stream cursor must be at the beginning of the font directory.  */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_font_dir( TT_Face face,
                       FT_Stream stream )
{
    SFNT_HeaderRec sfnt;
    FT_Error error;
    FT_Memory memory = stream->memory;
    TT_TableRec *entry;
    FT_Int nn;

    static const FT_Frame_Field offset_table_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  SFNT_HeaderRec

                    FT_FRAME_START( 8 ),
                    FT_FRAME_USHORT( num_tables ),
                    FT_FRAME_USHORT( search_range ),
                    FT_FRAME_USHORT( entry_selector ),
                    FT_FRAME_USHORT( range_shift ),
                    FT_FRAME_END
            };


    FT_TRACE2(( "tt_face_load_font_dir: %08p\n", face ));

    /* read the offset table */

    sfnt.offset = FT_STREAM_POS( );

    if ( FT_READ_ULONG( sfnt.format_tag ) ||
         FT_STREAM_READ_FIELDS( offset_table_fields, &sfnt ))
    {
        goto Exit;

        /* many fonts don't have these fields set correctly */
    }
#if 0
        if ( sfnt.search_range != 1 << ( sfnt.entry_selector + 4 )        ||
             sfnt.search_range + sfnt.range_shift != sfnt.num_tables << 4 )
          return SFNT_Err_Unknown_File_Format;
#endif

    /* load the table directory */

    FT_TRACE2(( "-- Number of tables: %10u\n", sfnt.num_tables ));
    FT_TRACE2(( "-- Format version:   0x%08lx\n", sfnt.format_tag ));

    /* check first */
    error = check_table_dir( &sfnt, stream );
    if ( error )
    {
        FT_TRACE2(( "tt_face_load_font_dir:"
                    " invalid table directory for TrueType\n" ));

        goto Exit;
    }

    face->num_tables = sfnt.num_tables;
    face->format_tag = sfnt.format_tag;

    if ( FT_QNEW_ARRAY( face->dir_tables, face->num_tables ))
    {
        goto Exit;
    }

    if ( FT_STREAM_SEEK( sfnt.offset + 12 ) ||
         FT_FRAME_ENTER( face->num_tables * 16L ))
    {
        goto Exit;
    }

    entry = face->dir_tables;

    FT_TRACE2(( "\n"
                "  tag    offset    length   checksum\n"
                "  ----------------------------------\n" ));

    for ( nn = 0; nn < sfnt.num_tables; nn++ )
    {
        entry->Tag = FT_GET_TAG4( );
        entry->CheckSum = FT_GET_ULONG( );
        entry->Offset = FT_GET_LONG( );
        entry->Length = FT_GET_LONG( );

        /* ignore invalid tables */
        if ( entry->Offset + entry->Length > stream->size )
        {
            continue;
        }
        else
        {
            FT_TRACE2(( "  %c%c%c%c  %08lx  %08lx  %08lx\n",
                    ( FT_Char ) ( entry->Tag >> 24 ),
                    ( FT_Char ) ( entry->Tag >> 16 ),
                    ( FT_Char ) ( entry->Tag >> 8 ),
                    ( FT_Char ) ( entry->Tag ),
                    entry->Offset,
                    entry->Length,
                    entry->CheckSum ));
            entry++;
        }
    }

    FT_FRAME_EXIT( );

    FT_TRACE2(( "table directory loaded\n\n" ));

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_any                                                   */
/*                                                                       */
/* <Description>                                                         */
/*    Loads any font table into client memory.                           */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: The face object to look for.                             */
/*                                                                       */
/*    tag    :: The tag of table to load.  Use the value 0 if you want   */
/*              to access the whole font file, else set this parameter   */
/*              to a valid TrueType table tag that you can forge with    */
/*              the MAKE_TT_TAG macro.                                   */
/*                                                                       */
/*    offset :: The starting offset in the table (or the file if         */
/*              tag == 0).                                               */
/*                                                                       */
/*    length :: The address of the decision variable:                    */
/*                                                                       */
/*                If length == NULL:                                     */
/*                  Loads the whole table.  Returns an error if          */
/*                  `offset' == 0!                                       */
/*                                                                       */
/*                If *length == 0:                                       */
/*                  Exits immediately; returning the length of the given */
/*                  table or of the font file, depending on the value of */
/*                  `tag'.                                               */
/*                                                                       */
/*                If *length != 0:                                       */
/*                  Loads the next `length' bytes of table or font,      */
/*                  starting at offset `offset' (in table or font too).  */
/*                                                                       */
/* <Output>                                                              */
/*    buffer :: The address of target buffer.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_any( TT_Face face,
                  FT_ULong tag,
                  FT_Long offset,
                  FT_Byte *buffer,
                  FT_ULong *length )
{
    FT_Error error;
    FT_Stream stream;
    TT_Table table;
    FT_ULong size;


    if ( tag != 0 )
    {
        /* look for tag in font directory */
        table = tt_face_lookup_table( face, tag );
        if ( !table )
        {
            error = SFNT_Err_Table_Missing;
            goto Exit;
        }

        offset += table->Offset;
        size = table->Length;
    }
    else
    {
        /* tag == 0 -- the user wants to access the font file directly */
        size = face->root.stream->size;
    }

    if ( length && *length == 0 )
    {
        *length = size;

        return SFNT_Err_Ok;
    }

    if ( length )
    {
        size = *length;
    }

    stream = face->root.stream;
    /* the `if' is syntactic sugar for picky compilers */
    if ( FT_STREAM_READ_AT( offset, buffer, size ))
    {
        goto Exit;
    }

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_generic_header                                        */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the TrueType table `head' or `bhed'.                         */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
static FT_Error
tt_face_load_generic_header( TT_Face face,
                             FT_Stream stream,
                             FT_ULong tag )
{
    FT_Error error;
    TT_Header *header;

    static const FT_Frame_Field header_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_Header

                    FT_FRAME_START( 54 ),
                    FT_FRAME_ULONG ( Table_Version ),
                    FT_FRAME_ULONG ( Font_Revision ),
                    FT_FRAME_LONG  ( CheckSum_Adjust ),
                    FT_FRAME_LONG  ( Magic_Number ),
                    FT_FRAME_USHORT( Flags ),
                    FT_FRAME_USHORT( Units_Per_EM ),
                    FT_FRAME_LONG  ( Created[ 0 ] ),
                    FT_FRAME_LONG  ( Created[ 1 ] ),
                    FT_FRAME_LONG  ( Modified[ 0 ] ),
                    FT_FRAME_LONG  ( Modified[ 1 ] ),
                    FT_FRAME_SHORT ( xMin ),
                    FT_FRAME_SHORT ( yMin ),
                    FT_FRAME_SHORT ( xMax ),
                    FT_FRAME_SHORT ( yMax ),
                    FT_FRAME_USHORT( Mac_Style ),
                    FT_FRAME_USHORT( Lowest_Rec_PPEM ),
                    FT_FRAME_SHORT ( Font_Direction ),
                    FT_FRAME_SHORT ( Index_To_Loc_Format ),
                    FT_FRAME_SHORT ( Glyph_Data_Format ),
                    FT_FRAME_END
            };


    error = face->goto_table( face, tag, stream, 0 );
    if ( error )
    {
        goto Exit;
    }

    header = &face->header;

    if ( FT_STREAM_READ_FIELDS( header_fields, header ))
    {
        goto Exit;
    }

    FT_TRACE3(( "Units per EM: %4u\n", header->Units_Per_EM ));
    FT_TRACE3(( "IndexToLoc:   %4d\n", header->Index_To_Loc_Format ));

    Exit:
    return error;
}


FT_LOCAL_DEF( FT_Error )
tt_face_load_head( TT_Face face,
                   FT_Stream stream )
{
    return tt_face_load_generic_header( face, stream, TTAG_head);
}


#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS

FT_LOCAL_DEF( FT_Error )
tt_face_load_bhed( TT_Face face,
                   FT_Stream stream )
{
    return tt_face_load_generic_header( face, stream, TTAG_bhed);
}

#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_max_profile                                           */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the maximum profile into a face object.                      */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_maxp( TT_Face face,
                   FT_Stream stream )
{
    FT_Error error;
    TT_MaxProfile *maxProfile = &face->max_profile;

    static const FT_Frame_Field maxp_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_MaxProfile

                    FT_FRAME_START( 6 ),
                    FT_FRAME_LONG  ( version ),
                    FT_FRAME_USHORT( numGlyphs ),
                    FT_FRAME_END
            };

    static const FT_Frame_Field maxp_fields_extra[] =
            {
                    FT_FRAME_START( 26 ),
                    FT_FRAME_USHORT( maxPoints ),
                    FT_FRAME_USHORT( maxContours ),
                    FT_FRAME_USHORT( maxCompositePoints ),
                    FT_FRAME_USHORT( maxCompositeContours ),
                    FT_FRAME_USHORT( maxZones ),
                    FT_FRAME_USHORT( maxTwilightPoints ),
                    FT_FRAME_USHORT( maxStorage ),
                    FT_FRAME_USHORT( maxFunctionDefs ),
                    FT_FRAME_USHORT( maxInstructionDefs ),
                    FT_FRAME_USHORT( maxStackElements ),
                    FT_FRAME_USHORT( maxSizeOfInstructions ),
                    FT_FRAME_USHORT( maxComponentElements ),
                    FT_FRAME_USHORT( maxComponentDepth ),
                    FT_FRAME_END
            };


    error = face->goto_table( face, TTAG_maxp, stream, 0 );
    if ( error )
    {
        goto Exit;
    }

    if ( FT_STREAM_READ_FIELDS( maxp_fields, maxProfile ))
    {
        goto Exit;
    }

    maxProfile->maxPoints = 0;
    maxProfile->maxContours = 0;
    maxProfile->maxCompositePoints = 0;
    maxProfile->maxCompositeContours = 0;
    maxProfile->maxZones = 0;
    maxProfile->maxTwilightPoints = 0;
    maxProfile->maxStorage = 0;
    maxProfile->maxFunctionDefs = 0;
    maxProfile->maxInstructionDefs = 0;
    maxProfile->maxStackElements = 0;
    maxProfile->maxSizeOfInstructions = 0;
    maxProfile->maxComponentElements = 0;
    maxProfile->maxComponentDepth = 0;

    if ( maxProfile->version >= 0x10000L )
    {
        if ( FT_STREAM_READ_FIELDS( maxp_fields_extra, maxProfile ))
        {
            goto Exit;
        }

        /* XXX: an adjustment that is necessary to load certain */
        /*      broken fonts like `Keystrokes MT' :-(           */
        /*                                                      */
        /*   We allocate 64 function entries by default when    */
        /*   the maxFunctionDefs value is smaller.              */

        if ( maxProfile->maxFunctionDefs < 64 )
        {
            maxProfile->maxFunctionDefs = 64;
        }

        /* we add 4 phantom points later */
        if ( maxProfile->maxTwilightPoints > ( 0xFFFFU - 4 ))
        {
            FT_TRACE0(( "tt_face_load_maxp:"
                        " too much twilight points in `maxp' table;\n"
                        "                  "
                        " some glyphs might be rendered incorrectly\n" ));

            maxProfile->maxTwilightPoints = 0xFFFFU - 4;
        }

        /* we arbitrarily limit recursion to avoid stack exhaustion */
        if ( maxProfile->maxComponentDepth > 100 )
        {
            FT_TRACE0(( "tt_face_load_maxp:"
                        " abnormally large component depth (%d) set to 100\n",
                    maxProfile->maxComponentDepth ));
            maxProfile->maxComponentDepth = 100;
        }
    }

    FT_TRACE3(( "numGlyphs: %u\n", maxProfile->numGlyphs ));

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_name                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the name records.                                            */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_name( TT_Face face,
                   FT_Stream stream )
{
    FT_Error error;
    FT_Memory memory = stream->memory;
    FT_ULong table_pos, table_len;
    FT_ULong storage_start, storage_limit;
    FT_UInt count;
    TT_NameTable table;

    static const FT_Frame_Field name_table_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_NameTableRec

                    FT_FRAME_START( 6 ),
                    FT_FRAME_USHORT( format ),
                    FT_FRAME_USHORT( numNameRecords ),
                    FT_FRAME_USHORT( storageOffset ),
                    FT_FRAME_END
            };

    static const FT_Frame_Field name_record_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_NameEntryRec

                    /* no FT_FRAME_START */
                    FT_FRAME_USHORT( platformID ),
                    FT_FRAME_USHORT( encodingID ),
                    FT_FRAME_USHORT( languageID ),
                    FT_FRAME_USHORT( nameID ),
                    FT_FRAME_USHORT( stringLength ),
                    FT_FRAME_USHORT( stringOffset ),
                    FT_FRAME_END
            };


    table = &face->name_table;
    table->stream = stream;

    error = face->goto_table( face, TTAG_name, stream, &table_len );
    if ( error )
    {
        goto Exit;
    }

    table_pos = FT_STREAM_POS( );


    if ( FT_STREAM_READ_FIELDS( name_table_fields, table ))
    {
        goto Exit;
    }

    /* Some popular Asian fonts have an invalid `storageOffset' value   */
    /* (it should be at least "6 + 12*num_names").  However, the string */
    /* offsets, computed as "storageOffset + entry->stringOffset", are  */
    /* valid pointers within the name table...                          */
    /*                                                                  */
    /* We thus can't check `storageOffset' right now.                   */
    /*                                                                  */
    storage_start = table_pos + 6 + 12 * table->numNameRecords;
    storage_limit = table_pos + table_len;

    if ( storage_start > storage_limit )
    {
        FT_ERROR(( "tt_face_load_name: invalid `name' table\n" ));
        error = SFNT_Err_Name_Table_Missing;
        goto Exit;
    }

    /* Allocate the array of name records. */
    count = table->numNameRecords;
    table->numNameRecords = 0;

    if ( FT_NEW_ARRAY( table->names, count ) ||
         FT_FRAME_ENTER( count * 12 ))
    {
        goto Exit;
    }

    /* Load the name records and determine how much storage is needed */
    /* to hold the strings themselves.                                */
    {
        TT_NameEntryRec *entry = table->names;


        for ( ; count > 0; count-- )
        {
            if ( FT_STREAM_READ_FIELDS( name_record_fields, entry ))
            {
                continue;
            }

            /* check that the name is not empty */
            if ( entry->stringLength == 0 )
            {
                continue;
            }

            /* check that the name string is within the table */
            entry->stringOffset += table_pos + table->storageOffset;
            if ( entry->stringOffset < storage_start ||
                 entry->stringOffset + entry->stringLength > storage_limit )
            {
                /* invalid entry - ignore it */
                entry->stringOffset = 0;
                entry->stringLength = 0;
                continue;
            }

            entry++;
        }

        table->numNameRecords = ( FT_UInt ) ( entry - table->names );
    }

    FT_FRAME_EXIT( );

    /* everything went well, update face->num_names */
    face->num_names = ( FT_UShort ) table->numNameRecords;

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_free_names                                                 */
/*                                                                       */
/* <Description>                                                         */
/*    Frees the name records.                                            */
/*                                                                       */
/* <Input>                                                               */
/*    face :: A handle to the target face object.                        */
/*                                                                       */
FT_LOCAL_DEF( void )
tt_face_free_name( TT_Face face )
{
    FT_Memory memory = face->root.driver->root.memory;
    TT_NameTable table = &face->name_table;
    TT_NameEntry entry = table->names;
    FT_UInt count = table->numNameRecords;


    if ( table->names )
    {
        for ( ; count > 0; count--, entry++ )
        {
            FT_FREE( entry->string );
            entry->stringLength = 0;
        }

        /* free strings table */
        FT_FREE( table->names );
    }

    table->numNameRecords = 0;
    table->format = 0;
    table->storageOffset = 0;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_cmap                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the cmap directory in a face object.  The cmaps themselves   */
/*    are loaded on demand in the `ttcmap.c' module.                     */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: A handle to the input stream.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */

FT_LOCAL_DEF( FT_Error )
tt_face_load_cmap( TT_Face face,
                   FT_Stream stream )
{
    FT_Error error;


    error = face->goto_table( face, TTAG_cmap, stream, &face->cmap_size );
    if ( error )
    {
        goto Exit;
    }

    if ( FT_FRAME_EXTRACT( face->cmap_size, face->cmap_table ))
    {
        face->cmap_size = 0;
    }

    Exit:
    return error;
}



/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_os2                                                   */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the OS2 table.                                               */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: A handle to the input stream.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_os2( TT_Face face,
                  FT_Stream stream )
{
    FT_Error error;
    TT_OS2 *os2;

    static const FT_Frame_Field os2_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_OS2

                    FT_FRAME_START( 78 ),
                    FT_FRAME_USHORT( version ),
                    FT_FRAME_SHORT ( xAvgCharWidth ),
                    FT_FRAME_USHORT( usWeightClass ),
                    FT_FRAME_USHORT( usWidthClass ),
                    FT_FRAME_SHORT ( fsType ),
                    FT_FRAME_SHORT ( ySubscriptXSize ),
                    FT_FRAME_SHORT ( ySubscriptYSize ),
                    FT_FRAME_SHORT ( ySubscriptXOffset ),
                    FT_FRAME_SHORT ( ySubscriptYOffset ),
                    FT_FRAME_SHORT ( ySuperscriptXSize ),
                    FT_FRAME_SHORT ( ySuperscriptYSize ),
                    FT_FRAME_SHORT ( ySuperscriptXOffset ),
                    FT_FRAME_SHORT ( ySuperscriptYOffset ),
                    FT_FRAME_SHORT ( yStrikeoutSize ),
                    FT_FRAME_SHORT ( yStrikeoutPosition ),
                    FT_FRAME_SHORT ( sFamilyClass ),
                    FT_FRAME_BYTE  ( panose[ 0 ] ),
                    FT_FRAME_BYTE  ( panose[ 1 ] ),
                    FT_FRAME_BYTE  ( panose[ 2 ] ),
                    FT_FRAME_BYTE  ( panose[ 3 ] ),
                    FT_FRAME_BYTE  ( panose[ 4 ] ),
                    FT_FRAME_BYTE  ( panose[ 5 ] ),
                    FT_FRAME_BYTE  ( panose[ 6 ] ),
                    FT_FRAME_BYTE  ( panose[ 7 ] ),
                    FT_FRAME_BYTE  ( panose[ 8 ] ),
                    FT_FRAME_BYTE  ( panose[ 9 ] ),
                    FT_FRAME_ULONG ( ulUnicodeRange1 ),
                    FT_FRAME_ULONG ( ulUnicodeRange2 ),
                    FT_FRAME_ULONG ( ulUnicodeRange3 ),
                    FT_FRAME_ULONG ( ulUnicodeRange4 ),
                    FT_FRAME_BYTE  ( achVendID[ 0 ] ),
                    FT_FRAME_BYTE  ( achVendID[ 1 ] ),
                    FT_FRAME_BYTE  ( achVendID[ 2 ] ),
                    FT_FRAME_BYTE  ( achVendID[ 3 ] ),

                    FT_FRAME_USHORT( fsSelection ),
                    FT_FRAME_USHORT( usFirstCharIndex ),
                    FT_FRAME_USHORT( usLastCharIndex ),
                    FT_FRAME_SHORT ( sTypoAscender ),
                    FT_FRAME_SHORT ( sTypoDescender ),
                    FT_FRAME_SHORT ( sTypoLineGap ),
                    FT_FRAME_USHORT( usWinAscent ),
                    FT_FRAME_USHORT( usWinDescent ),
                    FT_FRAME_END
            };

    static const FT_Frame_Field os2_fields_extra[] =
            {
                    FT_FRAME_START( 8 ),
                    FT_FRAME_ULONG( ulCodePageRange1 ),
                    FT_FRAME_ULONG( ulCodePageRange2 ),
                    FT_FRAME_END
            };

    static const FT_Frame_Field os2_fields_extra2[] =
            {
                    FT_FRAME_START( 10 ),
                    FT_FRAME_SHORT ( sxHeight ),
                    FT_FRAME_SHORT ( sCapHeight ),
                    FT_FRAME_USHORT( usDefaultChar ),
                    FT_FRAME_USHORT( usBreakChar ),
                    FT_FRAME_USHORT( usMaxContext ),
                    FT_FRAME_END
            };


    /* We now support old Mac fonts where the OS/2 table doesn't  */
    /* exist.  Simply put, we set the `version' field to 0xFFFF   */
    /* and test this value each time we need to access the table. */
    error = face->goto_table( face, TTAG_OS2, stream, 0 );
    if ( error )
    {
        goto Exit;
    }

    os2 = &face->os2;

    if ( FT_STREAM_READ_FIELDS( os2_fields, os2 ))
    {
        goto Exit;
    }

    os2->ulCodePageRange1 = 0;
    os2->ulCodePageRange2 = 0;
    os2->sxHeight = 0;
    os2->sCapHeight = 0;
    os2->usDefaultChar = 0;
    os2->usBreakChar = 0;
    os2->usMaxContext = 0;

    if ( os2->version >= 0x0001 )
    {
        /* only version 1 tables */
        if ( FT_STREAM_READ_FIELDS( os2_fields_extra, os2 ))
        {
            goto Exit;
        }

        if ( os2->version >= 0x0002 )
        {
            /* only version 2 tables */
            if ( FT_STREAM_READ_FIELDS( os2_fields_extra2, os2 ))
            {
                goto Exit;
            }
        }
    }

    FT_TRACE3(( "sTypoAscender:  %4d\n", os2->sTypoAscender ));
    FT_TRACE3(( "sTypoDescender: %4d\n", os2->sTypoDescender ));
    FT_TRACE3(( "usWinAscent:    %4u\n", os2->usWinAscent ));
    FT_TRACE3(( "usWinDescent:   %4u\n", os2->usWinDescent ));
    FT_TRACE3(( "fsSelection:    0x%2x\n", os2->fsSelection ));

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_postscript                                            */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the Postscript table.                                        */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: A handle to the input stream.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_post( TT_Face face,
                   FT_Stream stream )
{
    FT_Error error;
    TT_Postscript *post = &face->postscript;

    static const FT_Frame_Field post_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_Postscript

                    FT_FRAME_START( 32 ),
                    FT_FRAME_ULONG( FormatType ),
                    FT_FRAME_ULONG( italicAngle ),
                    FT_FRAME_SHORT( underlinePosition ),
                    FT_FRAME_SHORT( underlineThickness ),
                    FT_FRAME_ULONG( isFixedPitch ),
                    FT_FRAME_ULONG( minMemType42 ),
                    FT_FRAME_ULONG( maxMemType42 ),
                    FT_FRAME_ULONG( minMemType1 ),
                    FT_FRAME_ULONG( maxMemType1 ),
                    FT_FRAME_END
            };


    error = face->goto_table( face, TTAG_post, stream, 0 );
    if ( error )
    {
        return error;
    }

    if ( FT_STREAM_READ_FIELDS( post_fields, post ))
    {
        return error;
    }

    /* we don't load the glyph names, we do that in another */
    /* module (ttpost).                                     */

    FT_TRACE3(( "FormatType:   0x%x\n", post->FormatType ));
    FT_TRACE3(( "isFixedPitch:   %s\n", post->isFixedPitch
                                        ? "  yes" : "   no" ));

    return SFNT_Err_Ok;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_pclt                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the PCL 5 Table.                                             */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: A handle to the input stream.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_pclt( TT_Face face,
                   FT_Stream stream )
{
    static const FT_Frame_Field pclt_fields[] =
            {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_PCLT

                    FT_FRAME_START( 54 ),
                    FT_FRAME_ULONG ( Version ),
                    FT_FRAME_ULONG ( FontNumber ),
                    FT_FRAME_USHORT( Pitch ),
                    FT_FRAME_USHORT( xHeight ),
                    FT_FRAME_USHORT( Style ),
                    FT_FRAME_USHORT( TypeFamily ),
                    FT_FRAME_USHORT( CapHeight ),
                    FT_FRAME_BYTES ( TypeFace, 16 ),
                    FT_FRAME_BYTES ( CharacterComplement, 8 ),
                    FT_FRAME_BYTES ( FileName, 6 ),
                    FT_FRAME_CHAR  ( StrokeWeight ),
                    FT_FRAME_CHAR  ( WidthType ),
                    FT_FRAME_BYTE  ( SerifStyle ),
                    FT_FRAME_BYTE  ( Reserved ),
                    FT_FRAME_END
            };

    FT_Error error;
    TT_PCLT *pclt = &face->pclt;


    /* optional table */
    error = face->goto_table( face, TTAG_PCLT, stream, 0 );
    if ( error )
    {
        goto Exit;
    }

    if ( FT_STREAM_READ_FIELDS( pclt_fields, pclt ))
    {
        goto Exit;
    }

    Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_gasp                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the `gasp' table into a face object.                         */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_gasp( TT_Face face,
                   FT_Stream stream )
{
    FT_Error error;
    FT_Memory memory = stream->memory;

    FT_UInt j, num_ranges;
    TT_GaspRange gaspranges = NULL;


    /* the gasp table is optional */
    error = face->goto_table( face, TTAG_gasp, stream, 0 );
    if ( error )
    {
        goto Exit;
    }

    if ( FT_FRAME_ENTER( 4L ))
    {
        goto Exit;
    }

    face->gasp.version = FT_GET_USHORT( );
    face->gasp.numRanges = FT_GET_USHORT( );

    FT_FRAME_EXIT( );

    /* only support versions 0 and 1 of the table */
    if ( face->gasp.version >= 2 )
    {
        face->gasp.numRanges = 0;
        error = SFNT_Err_Invalid_Table;
        goto Exit;
    }

    num_ranges = face->gasp.numRanges;
    FT_TRACE3(( "numRanges: %u\n", num_ranges ));

    if ( FT_QNEW_ARRAY( gaspranges, num_ranges ) ||
         FT_FRAME_ENTER( num_ranges * 4L ))
    {
        goto Exit;
    }

    face->gasp.gaspRanges = gaspranges;

    for ( j = 0; j < num_ranges; j++ )
    {
        gaspranges[ j ].maxPPEM = FT_GET_USHORT( );
        gaspranges[ j ].gaspFlag = FT_GET_USHORT( );

        FT_TRACE3(( "gaspRange %d: rangeMaxPPEM %5d, rangeGaspBehavior 0x%x\n",
                j,
                gaspranges[ j ].maxPPEM,
                gaspranges[ j ].gaspFlag ));
    }

    FT_FRAME_EXIT( );

    Exit:
    return error;
}


/* END */
